pearson



( NoModeL) 2 Sheets-Sheet 1. M. H. PEARSON.

SEWING MACHINE.

No. 536,891. Patented A pr. Z, 1895.

. Q C 6 v (No Model.) 2 Sheets-Sheet 2. M. H. PEARSON.

' SEWING MACHINE.

No. 536,891. Patented Apr..2, 1895.

Z B c ItlT/VESSES Allow: e J,

. NITED STATES PATENT Orrin,

MARSHALL HENRY PEARSON, OF LEICESTER, ENGLAND, ASSIGNOR TO THE JOHNOFLAHERTY COMPANY, OF MONTREAL, CANADA.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 536,891, dated April 2,1895.

Application filed August 1'7, 1894. Serial No. 520,593. (No model.)Patented in England March 29, 1893 1 To all whom it may concern.-

Be it known that I, MARSHALL HENRY PEAR- SON, a citizen of England,residing at Leicester, in the county of Leicester,England, have inventedcertain new and useful Improvements in Sewing-Machines, (for which Ihave received Letters, Patent of Great Britain, No. 6,656, dated March29, 1893,) of which the following is a specification.

This invention is applicable to most kinds ofsewing machines, but beingespecially useful with machines employing a waxed thread, as in thestitching of leather or the like, I will now describe it in thatconnection, it being understood that I do not restrict the applicationof my invention to that particular type of my machine.

The invention deals with the treatment of the thread as to the tension,the taking-up'or tightening of the loop, the locating of the lock in orupon the material being stitched, and so far as waxed and similarthreads are concerned, to the waxing of the thread.

The details of the invention will necessarily vary with the differenttypes of machines to which the invention is applied, notwithstandingthat the same features would be substantially present in all, and in theaccompanying drawings I have merely shown as an example my invention asapplied to a machine of the Thomas type.

In the drawings,Figures 1 and 2 are respectively an elevation and a planof the upper portion of a sewing machine provided with my improvements,showing the needle thread nipping device operated by the shuttle lever.Figs. 3 and 4, Sheet 2, are views respectively similar to Figs. 1 and 2,showing alternative mechanism for operating the thread nipping device.Fig. 5 is a face view and Fig. 6, a plan of the shuttle; and Figs. 7

, and 8 are respectively a front elevation and a plan of theneedle-thread waxing device.

Like letters indicate like parts throughout the drawings.

In applying my invention to a machine of, say, the Thomas type, asillustrated in the accompanying drawings, I place upon a suitable partof the frame work A, conveniently on top, a flat table A, conveniently apart of the frame casting, and of suitable dimensions vice 0 betweenthem, are penetrated by a bolt 0 conveniently square, as indicated indotted lines in Fig. 2, to prevent its turning and passing through thetable A and other desired portion of the casting or frame work A of themachine. The bolt C may be provided with a head or equivalent 0 adaptedto be engaged by any suitable moving part of the machine, by which thebolt (3 and its plates 0 O O can be drawn downward and thus grip thethread firmlybetween the plate 0 and the table A. In the Thomas machinethis may be conveniently arranged by forming a lug or equivalentprojection D upon the shuttle lever D, so that at the proper time itengages with the head (3 or other suitable part of the bolt 0 pulling itand the plates 0 O 0 down. Any suitable spring arrangement may beemployed to adjust the pressure or take oif unnecessary shock orjar inthe operation. When the pressure is relaxed the plates 0 C 0 lie uponthe thread Band hold it between the lower plate 0 and the table A bytheir own weight, supplemented if desired by a small spring 0 thepressure of which can be adjusted, and which may be conveniently in theform of a helical spring, as shown placed around a small screw 0 passingthrough the plates 0 O C and screwing into the table A, the pressure ofthe spring 0 in this arrangement being adjusted by screwing C more orless into A.

The alternative mechanism for operating the needle thread nippingdevice, shown in Figs. 3 and 4, consists of a lever D pivoted at D tothe frame work A, and at D to the bolt 0 and near its opposite or freeend, provided with an antifriction roller D drawn by a spring E againsta cam F on the shaft F, said cam effecting the raising of the lever D,bolt 0 plates O 0 O and spring E, drawing these parts downward wheneverthe cam F is turned into the position allowing their descent. It will beunderstood that the position of all the before described mechanism maybealtered but the same eifect obtained.

After passing the above described tension and nipping device, the threadB may be passed through a solution box G, if liquid wax be used, andfrom there through a guide II, preferably in the form of a staple asshown, and then round a pulley or equivalent I upon the needle bar I,and from there through a suitable tension or guide device J to theneedle K. The guide H may be formed in any desired manner, whether ofstamped metal, wire or other material, so longas it is provided with anopening in which the thread can traverse when carried backward andforward by the needle bar, this feature being provided for by what isherein designated an elongated thread guide. The operation of theseparts is as follows:-The needle K having under the influence of theneedle bar 1 and needle bar lever L pivoted at L to I, made its downwardstroke and drawn the thread B with it so far as necessary, returns,leaving the necessary loop through which the shuttle passes and thencontinues its upward journey. In ordinary machines during its upwardmovement, the eye of the needle K slides over the thread B, scraping thewax oif it and more or less damagingthethread. Inthe presentinstance thethread B travels up with the needle K while it passes through the Workthis being accomplishedin the following manner: WVhen the sh uttlo hasentered the needle thread loop at the proper moment the previouslydescribed nipping device A, O, C C 0 comes into play and holds thethread B so that no more can be drawn, and the needle bar I as it rises,has thus to take the thread B up with it and consequently it rises atthe same speed as the needle K, and there is no movement of the threadthrough the eye of the needle. To effect this, it is desirable that thepoint at which the thread is held against upward movement should be asfar as may conveniently be practicable from the needle bar I, or thepulley I over which it passes. In the present i11- stance this pointwould be the eye or opening G through which the thread B escapes fromthe solution box G. IVhen the needle has risen so high that it is clearof the work, and there is only a small portion of the thread left to bepulled in, it is desirable to pull up the thread more quickly throughthe work, and since the eye of the needle K is clear of the work, nodamage will result to the thread if it now slips through the eye. Thismay be effected by the before mentioned staple guide II. The point atwhich the thread passes over the pulley I on the needle bar I having nowrisen to or above the top of the staple H the thread instead of havingthe long radius from the solution box G or other fixed point G aspreviously mentioned has now an extremely short one with the result thatas the thread B cannot now accommodate itself to the movement of theneedle bar I it slips past the pulley I and draws back through the eyeof the needle K tightening the loop in the work in a direct pull fromthe pulley I to the work, thus pullingin and locking the shuttle thread.

The height of the top of the staple or equivalent guide l-I may beVaried after loosening a set screw or other device II, thereby causingmore or less thread to be pulled backward past pulley I, and by thismeans the precise point within the work at which the locking of the twothreads takes place can be varied so that the operator can regulate thedepth into the Work at which the locking takes place.

During the whole of the lastdescribed operations the thread B has beenlocked or nipped, but so soon as the needle K has reached the highestpoint of its travel, the nip is relaxed and the thread can again bedrawn whether by the needle K in its next downward stroke or tofacilitate the removal of the work from the machine.

The tightness of the stitching is effected by the tension upon theshuttle thread itself, and this I regulate in a manner which, for waxedthreads, is of considerable importance. The thread N from the shuttle 0,Figs. 5 and 6, passes through a slot 0 upon one side of the shuttle inthe usual way and then through a single hole 0 upon the opposite side ofthe shuttle. Over this hole is a spring 0 the pressure of which can beregulated and so arranged to allow of the pull of the thread N at eitherend of the shuttle O with the same amount of tension upon the thread inall positions. The edge of the shuttle closing in one side of the slot 0is deflected inward as shown in Fig. 5. By this means Iavoid passing thethread N through a number of holes and thus scraping it, and am able tosatisfactorily control the tightness of the work.

For the purpose of supplying the wax to the work without waxing more ofthe thread than is necessary, a well known device is that set forth inPearsons patent, No. 199,991, dated February 5, 1878, where the needlepoint dips into a cup kept supplied with melted wax, the cup beingsupported upon a lover or arm pivoted within a box and having anadjustment screw to regulate the depth to which the needle enters theWax and thus to regulate the amount of wax taken up at each stroke.

In the present arrangementI employ a similar device,but I pivot the cuplever'or arm P outside the box Q and employ preferably in connectionwith the adjustment screw P a sliding cam plate B, so arranged that whenmoved in one direction to the leftit elevates the lever P and the cup Pto the highest position, thus giving the needle K its full dip, and whenmoved in the opposite direction it allows the arm and cup to drop, sothat the needle does not dip into the wax in the cup. By this means thesupply of wax to the needle can be immediately checked, while theregulation by the screw P is just as perfect as before. If preferred,the screw P may be IIO entirely dispensed with, the cam plate R being soshaped as to afford the necessary amount of elevation to the armP andcup P more or less according to the position at which the cam plate R isplaced. Any convenient means may be employed to render the plate Rmovable and prevent it from moving from its appointed position by thevibration of the machine. For example, it may be connected by clips R tothe adjacent wall of the box Q, and be retained in position by a screw,spring tension device, rack and pawl or the like.

Having now particularlydescribed and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare-thatwhat I claim is 1. In a sewing machine, the combination with the needlebar and the thread guide car-- ried thereby; of a fixed guiding eye G ata distance from the needle bar; a vertically elongated staple H betweenthe needle bar and the fixed guiding eye; and a threaddocking device toact upon the thread prior to entering the fixed eye; whereby on thedownward movement of the needle bar the thread can move freely throughthe staple from the eye G as a center; while on the upward movement ofthe needle bar the thread can move from the upper end of the staple as acenter, substantially as shown and described.

2. In a sewing machine, the combination with a thread or needle-waxingdevice comprising a box such as Q and a cup arm such as P P, of anadjustable cam plate such as R, substantially as described andillustrated in the accompanying drawings.

